A five year study is proposed to assess the feasibility, effectiveness, and costs of a stepped approach to increase long- term smoking cessation rates in the defined population of a worksite. Key features of this study include: (1) identifying all smokers at the worksite; (2) providing ongoing active encouragement to each smoker to participate in smoking cessation activities; (3) offering each smoker increasingly intensive assistance in quitting smoking; (4) offering each smoker who achieves initial cessation a series of increasingly intensive aids to maintain cessation; (5) recycling those who fail to achieve initial cessation, or who relapse, through the increasingly intensive cessation activities: and (6) estimating the costs per worksite smoker and per long-term quitter of this approach. This stepped approach model is consistent with the medical model in which increasingly intensive and/or expensive therapies are successively tried until a cure is achieved. The participating employer in this study is King County. King County employs five thousand workers, including both white- collar and blue-collar workers, in 32 separate work units. Half of the work units will be randomized to the intervention arm and half to usual care. The procedures for this study include: (1) a recruitment sequence; (2) a cessation sequence; and (3) a relapse prevention sequence. In the recruitment sequence, all smokers will be contacted and invited to participate in the study. In the cessation and relapse prevention sequences, four steps (ordered from least to most intensive) are possible: (1) hotline counseling; (2) self-help materials; (3) group-help sessions; and (4) referral to smoker's physician for more intensive therapy. There are two primary outcomes of this study: (1) long-term smoking cessation rates (continuous abstinence from cigarettes for at least six months at the time of the final assessment); and (2) costs of the stepped approach per long-term quitter. This comprehensive, stepped approach, if successful and cost-effective, can easily be exported to other worksites and settings.